EP0560783A1

EP0560783A1 - Coating with high solid matter content, process for producing the same and its use as covering lacquer or as primer in industrial applications.

Info

Publication number: EP0560783A1
Application number: EP91918229A
Authority: EP
Inventors: Oswald Bodenmueller; Ulrich Kramm; Thomas Singe; Dieter Weber
Original assignee: BASF Lacke und Farben AG
Current assignee: BASF Coatings GmbH
Priority date: 1990-12-08
Filing date: 1991-10-24
Publication date: 1993-09-22
Anticipated expiration: 2011-10-24
Also published as: EP0560783B1; DK0560783T3; ES2099170T3; WO1992010550A1; ATE148152T1; DE4039220A1; DE59108514D1; BR9107157A

Abstract

A coating is disclosed based on polyesters and isocyanates, which is characterized by containing as a binder a mixture of (a) 30 to 94 wt% of at least a polyester resin containing hydroxyl groups, having a hydroxyl number from 40 to 140 mgKOH/g and an oil content from 25 to 57%; (b) 3 to 15 wt% of at least a branched polyester containing hydroxyl groups based on cycloaliphatic and/or aromatic di- and/or polycarboxylic acids with a hydroxyl number from 100 to 200 mgKO/g and a trifunctional and/or higher alcohol and/or carboxylic acid content of at least 15 moles %, referred to the alcohol and carboxylic acid total content; and (c) 3 to 15 wt % of at least one polyester modified by synthetic fatty acids having a hydroxyl number from 80 to 150 KOH/g and a synthetic fatty acid contect from 35 to 50 wt%, referred to the weight of the modified polyester. The sum of the parts by weight of components (a) to (c) equals 100 wt %.

Description

Coating agent with a high solids content, process for the production thereof and use of the coating agent for dec coating and as a primer in the industrial sector.

The present invention relates to a coating composition with a high solids content, which contains a binder component based on polyester and a hardener component based on isocyanate.

The present invention also relates to processes for the production of the coating compositions and for the coating of substrates, in which these coating compositions are used, and the use of the coating compositions.

Coating agents with a high solids content based on polyester are known. They often contain one or more hydroxy-functional components that react with a suitable curing agent. For example, DE-OS 31 02 969 discloses coating compositions based on polyester with a high solids content, which can be cured to give flexible and, at the same time, hard, weather-resistant top or finish layers. In addition to a curing agent and possibly an epichlorohydrin-bisphenol-A epoxy resin, these coating compositions contain a polyester polyol. The polyester polyol is the reaction Oil product from a mixture of an aromatic and an aliphatic dicarboxylic acid and a mixture of neopentyl glycol and at least one other hindered diol with two methylol groups which are directly 5a a cycloaliphatic or aromatic structure or bound to a tertiary carbon atom. A disadvantage of these coating compositions is that, particularly when applied by means of air atomization or by means of the airless spray process, there is no universal applicability over a wide range of processing parameters.

Further high-solids coating compositions based on the lδ-based polyester and alkyd resins are also described, for example, in EP-B-18051, EP-B-18052 and US Pat. No. 4,419,407.

In addition, some alkyd resin solutions with a high solids content and at the same time as low a viscosity as possible are commercially available, which are recommended for use in high-solids two-component paints. Examples include the following products: Alkydal LS 2843 from Bayer AG, Synthalat DRS 89-417 from Synthopol Chemie Dr. Rer. Pole. Koch 5GmbH & Co. KG and HALWEFTAL TN 2565 from Hüttenes-Albertus Chemische Werke GmbH.

Furthermore, from DE-PS 32 01 749 heat-curable, high-solids coating compositions are known which, as binding agents, contain a mixture of 15 to 60% by weight of an oil-free polyester containing alicyclic carboxylic acids as acid component, 5 to 40% by weight. an alkyd resin with an oil content of 15 to 50% and an OH number of 40 to 200, 5 to 40% by weight of an acrylic resin with an OH number of 20 to 200 and a number average molecular weight of 1000 up to 30000 and •• ■ contain 10 to 40% by weight of a crosslinking agent. However, these coating compositions have the disadvantage that the coating compositions cannot be dried sufficiently both at room temperature and under the usual conditions of forced drying.

DE-OS 22 31 474 also discloses heat-curable coating compositions based on at least one alkyd resin which contains 30 to 70% by weight of a drying oil and a polyisocyanate hardener. These coating compositions can contain up to 10% by weight, based on the weight of the binder, of a polymeric plasticizer. However, these coating compositions have the disadvantage that the solids content is too low.

Examination of this and similar prior art would show that it is often necessary in the field of polyester resin-based coating compositions to sacrifice one favorable property in order to improve another. For example, it is often difficult to provide a coating agent available to ^5, which is be applied in high solids contents and results in coatings which are tough and flexible and have good resistance to weathering and Chemikalienbeständig¬ ness. In practice, the requirement that the coating agents must be universally pigmentable and that they are applied using a wide variety of application methods, such as, for example, the airless spray process, the air mix spray process, the conventional air atomization, also often proves problematic. tionszerstäubern spraying methods or by means of rota ^5, must be applied. 1

The present invention is therefore based on the object of making available coating compositions which can be applied with relatively high solids contents using a wide variety of application processes and can be quickly cured at commercially usable temperatures, preferably at temperatures between room temperature and 140 ° C. Furthermore, the coating compositions should be universally pigmentable and should lead to coatings which, with a high degree of flexibility, also have a high surface hardness and, in addition to a high gloss, a good chemical resistance and, depending on the application, good if appropriate Show weather resistance. 5

Surprisingly, this object is achieved by a coating agent which contains a binder component based on polyester and a hardener component based on isocyanate, characterized in that the coating agent as a binder comprises a mixture of

a) 30 to 94% by weight of at least one hydroxyl-containing polyester resin with an OH number of 40 5 to 140 mg KOH / g and an oil content of 25 to 57%,

b) 3 to 50% by weight of at least one branched hydroxyl-containing polyester based on cycloaliphatic and / or aromatic di- and / or polycarboxylic acids with an OH number of 100 to 200 mgKOH / g and a content of tri- and / - or higher functional alcohols and / or carboxylic acids of at least 15 mol%, based on the total content of alcohols and carboxylic acids, and 1 c) 3 to 50 wt .-% of at least one modified polyester with fatty acids syntheti¬ rule ei¬ ner OH number of 80 to 150 mgKOH / g and an overall ⁵ halt of synthetic fatty acids of from 35 to

Contains 50% by weight, based on the weight of the modified polyester, the sum of the parts by weight of components a to c being 100% by weight.

The present invention also relates to processes for the production of these coating compositions, processes for coating substrates in which these coating compositions are used, and the use of the coating compositions.

It is surprising and was not foreseeable that the coating compositions with a relatively high solids content of preferably> 60% can be applied using a wide variety of application methods, such as, for example, using the airless spray process, the air mix spray process, the conventional air atomization spray process or by means of rotary atomization. In particular, the coating compositions have the advantage of being universally pigmentable. This means that a large number of customary inorganic and organic pigments can be incorporated without floating problems or pigment wetting problems occurring. It is also advantageous that the resulting coatings with good surface hardness at the same time have good flexibility and, in addition to a high gloss, also show good chemical resistance. When using aliphatic isocyanates as hardeners, the coatings are also characterized by good weather resistance. When using aromatic isocyanates as hardeners, The coating compositions also release the advantage of extremely rapid drying.

The individual components of the coating compositions according to the invention are now explained in more detail below.

It is essential to the invention that the coating agent as a binder is a mixture of

0a) 30 to 94% by weight, preferably 70 to 90% by weight, at least one hydroxyl-containing polyester resin with an OH number of 40 to 140 mgKOH / g, preferably 50 to 90 mgKOH / g and an oil content from 25 to 57%, preferably 40 to 50%, 5 b) 3 to 50% by weight, preferably 5 to 15% by weight, of at least one branched hydroxyl-containing polyester based on cycloaliphatic and / or aromatic di- and / or polycarboxylic acids with an OH number of 100 to 200 mgKOH / g, preferably 115 to 150 mgKOH / g, and with a content of trifunctional or higher-functional alcohols and / or carboxylic acids of at least 15 mol% and

c) 3 to 50% by weight, preferably 5 to 15% by weight, at least one polyester modified with synthetic fatty acids and having an OH number of 80 to 150 mgKOH / g, preferably 115 to 130 mgKOH / g , and with a content of synthetic fatty acids of 35 to 50 wt .-%, based on the weight of the modified polyester, contain, the sum of the proportions by weight of components a to c being 100 wt .-%. Both the weight data and the key figures of components a to c are based in each case on the 100% binders without solvent content. The polyester resins used as component a are prepared by the known methods (cf., for example, EP-A-237 749) by reaction in the melt or in organic solvents at temperatures of generally 200 to 260 ° C.

The oil length of the polyester resins is between 25 to 57%, preferably between 40 and 50%. Oil length is understood to mean the proportion of fatty acids in% by weight, based on the weight of the polyester resin (proportion of solid resin). The polyester resins a used according to the invention generally have acid numbers <50 mgKOH / g, preferably <10 mgKOH / g and iodine numbers <70 mg ₂ / g, preferably <50 mg ₂ . The hydroxyl equivalent weight of the polyester resins is preferably between 425 and 1700, particularly preferably between 900 and 1000.

The OH number of the polyester resins is between 40 and 140 mgKOH / g, preferably between 50 and 90 mgKOH / g. Polyester resin solutions are preferably used which, with a solids content of 60%, have viscosities between 25 and 60 s according to DIN 53 211 at 20 ° C. These polyester resins are preferably used as a solution with a solids content of> 70%, particularly preferably 2.80%.

For the production of the polyester resins used as component a, the raw materials usually used for the production of polyester resins can be used, the amounts of the individual components each having to be selected such that the polyester resins have the above-mentioned characteristics. 1

Preferred polyester resins are more highly functional with the use of aliphatic and / or cycloaliphatic and / or aromatic, preferably aromatic, dicarboxylic acids or suitable dicarboxylic acid derivatives, optionally in combination with small amounts, preferably 10 mol% (based on the carboxylic acid content) Carboxylic acids and optionally obtained in combination with aromatic monocarboxylic acids. 0

A preferred mixture of natural oils or fatty acids in a proportion of 7 to 25% by weight, preferably 7 to 14% by weight, at least one saturated fatty acid, 30 to 35% by weight, preferably 30 to 35% by weight, of at least one fatty acid with 2 double bonds per molecule and 40 to 57% by weight, preferably 51 to 57% by weight, of at least one fatty acid having 3 or more double bonds per molecule and optionally up to 3% by weight of further long-chain fatty acids. All percentages by weight are based on the weight of the resin.

Fatty acids of the soybean oil type are preferably used as the fatty acid component, but there are also other oils which dry, such as e.g. Tung oil, tall oil, linseed oil, dehydrated castor oil, china wood oil, mixtures thereof and the like. . suitable drying oils. The fatty acids can also be used in the form of their glycerides.

Examples of suitable aromatic di- and / or polycarboxylic acids which can be used together with the fatty acids for the production of the polyester resins a are phthalic acid, terephthalic acid, isophthalic acid, trimellitic acid, pyroellitic acid, 2-methyltrimellitic acid as well as naphthalenedi- and tricarboxylic acids u. , Examples of suitable aliphatic di- and polycarboxylic acids are succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, acelainic acid, sebacic acid, 2-ethylhexanoic acid, isononanoic acid and others. Unsaturated carboxylic acids, for example maleinic acid, fumaric acid, can also be used. Itaconic acid, citraconic acid, etc. can also be used.

Examples of suitable cycloaliphatic di- and polycarboxylic acids are tetrahydrophthalic acid, hexahydro phthalic acid, 1,4-cyclohexanedicarboxylic acid, methylcyclohexanedicarboxylic acid and others.

Examples of suitable aromatic monocarboxylic acids are benzoic acid, alkyl-substituted benzoic acids, l ^ naphthenic acids and their isomers, abietic acid and their isomers and others, preferably benzoic acid.

Particularly preferred polyester resins are obtained by using phthalic acid or mixtures of phthalic acid and adipic acid, optionally together with aromatic monocarboxylic acids and the above-mentioned fatty acids.

The carboxylic acids mentioned can be used for the production of the polyester resins in the form of the free acids or suitable derivatives capable of esterification (e.g. anhydrides) or suitable derivatives capable of transesterification (e.g. methyl esters).

Aliphatic and / or aromatic and / or cycloaliphatic straight-chain or branched diols and / or polyols can be used as the alcohol component for the construction of the polyester resins. Aliphatic diols and / or polyols are preferably used. Examples of suitable aliphatic diols and polyols 5 are glycols, such as, for example, ethylene glycol, propylene glycol, neopentyl glycol, 1,4-butanediol, 1,6-hexanediol, 2,2,4- τrimethyl-l, 3-ρentanediol, diethylene glycol, triethylene glycol and triols and polyols, such as trimethylolethane, trimethylolpropane, glycerol, ethoxylated and propoxylated glycerol, pentaerythritol,

⁵ Dipentaerythritol, ditrimethylolpropane, mannitol, sorbitol and others. Pentaerythritol and trimethylolpropane are preferably used.

Various commercially available, high-solids and low-viscosity polyester resin solutions which have the abovementioned characteristics are also suitable for use in the coating compositions according to the invention.

5A1S of further binder component b, the coating compositions according to the invention contain at least one branched hydroxyl-containing polyester based on cycloaliphatic and / or aromatic di- and / or polycarboxylic acids. These branched polyesters used as component b 0 _e have OH numbers of 100 to 200 mgKOH / g, preferably 115 to 150 mgKOH / g. The acid number of these polyesters is generally below 30 mgKOH / g, preferably below 15 mgKOH / g. The iodine number of these polyesters is usually less than 50 mgl ₂ / g, preferably less than 10 mgl ₂ / g. The hydroxyl equivalent die¬ ser polyester is preferably 340-600, more preferably between 380 and 475. Preferably, the polyester resin solutions are used, the egg at nem Feststof ^'fgehalt of 60% and a viscosity between 2.5 and 4.0 dPas at 23 ° C. This branched hydroxyl-containing polyester is preferably used in the coating compositions as a solution with a solids content of 70%. The polyesters used as component b can be produced by the customary methods (cf., for example, Houben Weyl, Methods of Organic Chemistry, 4th Edition, Volume 14/2, Georg Thieme Verlag, Stuttgart 1961). Suitable for the production of these branched hydroxyl-containing polyesters are cycloaliphatic and / or aromatic di- and / or polycarboxylic acids, preferably cycloaliphatic di- and / or polycarboxylic acids as well as aliphatic and / or cycloaliphatic 10 and / or aromatic di- and / or polyols, aliphatic diols and / or polyols are preferably used as the alcohol component. The structural components of this polyester are to be selected such that at least 15 mol%, based on the total amount of acid component plus alcohol component used, of the structural components are tri- and / or higher-functional, it being possible to use tri- and / or higher-functional alcohols or tri- and / or higher-functional carboxylic acids or mixtures of tri- and / or higher-functional alcohols and tri- and / or higher-functional carboxylic acids. Examples of suitable structural components are the cycloaliphatic carboxylic acids, aromatic 5-carboxylic acids and aliphatic alcohols already mentioned in the description of the polyester resins, so that reference is only made to pages 8 to 10 of the description here.

The coating compositions according to the invention contain, as binder component c, at least one polyester modified with synthetic fatty acids, with an OH number of 80 to 150 mgKOH / g, preferably 115 to 130 mgKOH / g and a content of synthetic fatty acids from 35 to 50% by weight, based on the weight of the 5-modified polyester. This polyester 1 usually have acid numbers below 50 mgKOH / g, preferably below 10 mgKOH / g and iodine numbers below 50 mg / g ₂ , preferably <10 mg / g ₂ . The hydroxyl equivalent weight of these polyesters is preferably between 360 and 710, particularly preferably between 430 and 490. Polyester resin solutions are preferably used which, at a solids content of 70%, have a viscosity between 5 and 7 dPas at 23 ° C. In the coating compositions, this modified, hydroxyl-containing polyester is preferably used as a solution with a solids content of ± .70%.

The polyesters used as component c can be prepared by the customary methods (see, for example, Houben lδweyl, Methods of Organic Chemistry, 4th Edition, Volume 14/2, Georg Thieme Verlag, Stuttgart 1961).

To modify this polyester used as component c, 35 to 2050% by weight, based on the weight of the modified polyester (solid resin), of synthetic fatty acids are used in the production. Examples of suitable fatty acids are isononanoic acid and 2-ethylhexyl acid.

For the production of the polyesters used as component c, together with the synthetic fatty acids, further aliphatic and / or cycloaliphatic and / or aromatic di- and / or polycarbonic acids, optionally together with small amounts of monocarboxylic acid, can be used , are used. Aliphatic di-, tri- and polyols are particularly suitable as alcohol components for the production of these polyesters. Examples of suitable structural components are the 5 alcohols and carboxylic acids already mentioned in the description of the polyesters a, with the exception of the fatty acids listed there, so that reference is made here only to pages 8 to 10 of the description. 1

If appropriate, at least one hydroxyl-containing acrylate copolymer can be used in the coating compositions according to the invention together with the polyester components a to c as a further binder component. Suitable acrylate copolymers are obtained by copolymerizing a hydroxyl group-containing acrylic monomer with one or more radical-polymerizable unsaturated monomers in a conventional manner.

Examples of suitable hydroxyl-containing monomers are C2 to C8 hydroxyalkyl esters of acrylic and methacrylic acid, such as e.g. Hydroxyethyl acrylate, hydroxy

Ethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate etc. These monomers containing hydroxyl groups can be used either individually or as a mixture of two or more. Any compounds with a free-radically polymerizable ethylenically unsaturated bond can be used as monomers which are copolymerizable with the hydroxyl-containing monomer. They can be selected broadly from such compounds in accordance with the desired properties of the acrylate copolymer. Typical examples of such monomers are alkyl esters of acrylic and methacrylic acid, vinylaromatic compounds, ot ^ -unsaturated carboxylic acids, vinyl monomers containing glycidyl groups, acrylic or methacrylic acid amides and the like. . For further details regarding suitable monomers and production conditions, reference is made to DE-PS-32 01 749, pages 3 to 5.

The 5 acrylate copolymers used as a further binder component usually have OH numbers I from 20 to 200 mgKOH / g and are preferably low molecular weight.

For curing of the coating ⁵ of the invention Bin¬ medium via a reaction of the hydroxyl groups demittels containing coating agent minde¬ least one di- and / or polyisocyanate.

When using aliphatic and / or cycloaliphatic isocyanates, coatings with high resistance to weathering can be produced. The aliphatic and / or cycloaliphatic isocyanates are preferably added to the coating compositions in such an amount that the equivalent ratio of the OH groups of the binder (sum of the OH groups of the 5 components a to c and optionally further components containing hydroxyl groups) to the NCO Groups of the hardener is between 1: 1 and 1: 1.1.

If aromatic isocyanates are used, coating agents are obtained with accelerated drying. Owing to the poorer weather resistance, these coating compositions are mainly used for the production of coatings for interior applications. The aromatic isocyanates are preferably added to the coating compositions in an amount such that the equivalent ratio of the OH groups of the binder (sum of the OH groups of components a to c and any other components containing hydroxyl groups) to the NCO groups of the κärters between 1: 0.5 and 1: 0.8.

Examples of suitable aliphatic or cycloalipha¬ diagram di- and polyisocyanates are hexamethylene diisocyanate, decamethylene diisocyanate, isophorone _C Yanat, dicyclohexylmethane-4,4'-diisocyanate, isocyanate Lysindi- as well as di- and trimerized derivatives of these Isocyanates.

Examples of other suitable aliphatic and cycloaliphatic isocyanates are also the products commercially available under the following names: Desmodur®N 75, Desmodur® 3200, Desmodur®N 3300, Desmodur® N 3390, Desmodui®Z 4370 and Desmodui® LS 2550 from Bayer AG, Basonate® PLR 8638 from BASF AG and polyisocyanate IPDI T 1890 from Hüls 10AG.

Examples of suitable aromatic di- and polyisocyanates are diphenylmethane-4,4'-diisocyanate, diphenylene-4,4'-diisocyanate, 2,4- and 2,6-tolylene diisocyanate.

Ionate, m-phenylene diisocyanate, p-phenylene diisocyanate,

1,5-naphthalene diisocyanate, 3,3 '-dimethyl-4,4'-biphenylene diisocyanate, 3,3'-dimethoxy-4,4'-biphenylene diisocyanate, 3,3'-diphenyl-4,4 '- biphenylene, 4, '-Biphenylendiisocyanat 1,3,5-benzene triisocyanates Yanat, 0 _C, para, para', para ^'•' -Triphenylmethantriiso- diisocyanate and xylylene.

An aliphatic or cycloaliphatic isocyanate ULTRASONIC or a micro 5 is preferred as the isocyanate component _sc hung various aliphatic and / or cycloali¬ phatic isocyanates used in which the nat Isocya¬ or in the case of mixtures, the mixture has an NCO content from 10 to 25 %, based on the isocyanate without solvent. The isocyanate or the mixture of different isocyanates preferably has a viscosity of 100 to 5000 mPas at 20 ° C. in the use state, ie in the form in which the isocyanate component is used in the coating agents. To adjust this viscosity, 5 solvents can be added to the isocyanate component if necessary. 1Besonders preferred coating agents are polyisocyanate having an NCO content of 18 to 25% and a viscosity of 100-5200 mPas at 20 by the use of at least one aliphatic and / or cycloaliphatic ^β C, in each case based on the isocyanate without Lδsungsmittelanteil obtained. If appropriate, further di- and / or polyisocyanates, preferably aliphatic and / or cycloaliphatic 10isocyanates, can be used together with this aliphatic, low-viscosity polyisocyanate.

In order to increase the curing rate of the oxidative drying of the coating compositions according to the invention, it is also preferred to add about 0.001 to 3% by weight, based on the weight of the polyester component a (solid resin content), of at least one metallic drying agent. Typical drying agents that are used are metal salts (cyclo) aliphatic, natural or synthetic acids, such as metal salts of linoleic acid, naphthenic acid, octanoic acid, 2-ethylhexanoic acid, oleic acid and the like. ., Preferably metal salts of octanoic acid are used. Suitable metals include cobalt, manganese, lead, zirconium, calcium, zinc and bismuth. If the curing agent is a polyisocyanate, 5 as coating agent can contain at least one curing catalyst from 0.01 to 2.5% by weight, based on the weight of the film-forming mixture. Organometallic compounds such as, for example, dibutyltin dilaurate, zinc octoate, dibutyltin di-2-ethylhexoate, tin II-octoate, tin-II-oleate, zinc naphthenate, vanadium acetylacetonate or zirconium acetylacetate are usually used as the curing catalyst set. Also suitable as a curing catalyst are tertiary amines, such as triethylenediamine, pyχidin, dimethylaniline and methylmorpholine. The hardening catalyst can either be added to the base lacquer or the hardener component. 1

It is assumed that it is precisely through the combination of the two curing mechanisms - the oxidative drying via the polyester resin a and the isocyanate crosslinking via the reaction of the hydroxyl groups of the binder components - and nesting of the two networks that the requirement profile is achieved. The universal pigmentability and applicability of the coating compositions, which cannot be achieved by the sole use of binder component a in combination with isocyanate hardeners and drying agents, should be emphasized in particular.

As already mentioned, all commercially available inorganic and organic pigments are suitable for pigmenting the coating compositions, for example metal oxides, such as Titanium dioxide, zinc oxide, iron oxides and the like. The like, metal hydroxides, metal flakes, metal powder, effect pigments, chromates, such as Lead chromate, sulfides, sulfates, carbonates, carbon black, iron blue dyes and organic pigments.

The pigments are used in the coating compositions according to the invention in customary amounts, preferably in an amount of 0 to 40% by weight, preferably 2 to 30% by weight, based on the total weight of the coating composition.

Furthermore, the coating compositions according to the invention can also contain fillers in customary amounts, preferably in an amount of 0 to 40% by weight, particularly preferably 5 to 20% by weight, based on the total weight of the coating composition. Suitable fillers are, for example, natural or synthetic barium sulfates, aluminum silicates, magnesium silicates 1 Liquates, silicas, talc, mica, kaolin, chalk, etc. Synthetic barium sulfate is preferably used to adjust the solids content and the rheology setting.

5

If necessary, the coating composition can furthermore contain customary auxiliaries and additives in conventional amounts, preferably 0.1 to 5.0% by weight, based on the total weight of the coating composition. Examples of suitable auxiliaries and additives are dispersing aids, anti-settling agents, leveling agents, defoamers, stabilizers, wetting agents and the like. . Particularly with regard to defoaming, it has surprisingly been found that the coating compositions according to the invention or the binder mixture inherently show low foam stabilization, so that there is universal processability. In particular, in the case of application by the airless spraying process and with the aid of a high-speed rotary bell, the foam formation which is otherwise typical for two-component paints occurs here only to a minor extent.

The coating compositions of the invention are also distinguished by the fact that they can be processed with a high solids content. The coating compositions (including hardener component) usually have a solids content of> 60%, preferably> 65%. The solvent content of the ready-to-use coating compositions according to the invention fluctuates in accordance with the different requirements for the viscosity of the coating compositions in the various application processes. If the coating compositions according to the invention are applied by the airless spray process, the processing viscosity of the paints is generally between 18 and 20 s run-out time in the DIN 4 cup. The invention Coating compositions of this type usually have a solids content of> 65% in this processing viscosity of 18 to 20 s run-out time in a DIN 4 cup at 20 ° C. If the coating compositions according to the invention are applied by other methods, the processing viscosity of the lacquer may well be higher. The solids content of the coating compositions is correspondingly higher. For example, the coating agents usually have a solids content of 2.70% at a processing viscosity of 30 s in accordance with DIN 53 211 (high-speed rotary bell).

Aliphatic and aromatic are particularly suitable for adjusting the viscosity of the coating compositions according to the invention White spirit, solvent naphtha ^ H various Solvessά _* * ^ - and Shellsol ^ types, deasol, xylene, toluene and others as well as esters such as methoxypropyl acetate, butyl acetate and 0-butylglycol acetate are suitable.

The coating compositions according to the invention are usually produced by mixing and, if appropriate, dispersing the individual components. The coating compositions are preferably formulated as a 2-component system. That is, a solution of the isocyanate component is in a package, and a solution or dispersion of the binder component and the other constituents, such as pigments, is in a separate package. The two solutions or dispersions are carefully mixed immediately before the coating compositions are applied. The separation of the two components is usually necessary because the so-called pot life of the mixtures is short. The 5 isocyanate component usually reacts with the hydroxyl groups of the binder even at room temperature at high speed. 1

Instead of the two-component system described above, a one-component system can also be produced if the reactive groups of the isocyanate component are blocked with a blocking agent such as e.g. Methyl ethyl ketoxime, malonic acid esters and the like. Ä., are blocked. When the applied coating agents are heated to temperatures of up to 140 ° C. during the stoving process, the blocking agent IO is released again, as a result of which the reaction of the

Hydroxyl groups of the binder with the polyester is possible. However, because of the need to release the blocking agent, such coating compositions can only be cured under forced conditions.

The pigments are incorporated into the coating compositions by customary methods, e.g. by grinding the pigments with part of the binders used. 0

The coating compositions according to the invention can be applied universally. For example, they can be sprayed using the airless spray process, the air mix spray process, the conventional air atomization spray process, 5 with the aid of rotary atomizers, such as a high-speed rotary bell, and by flooding, rolling, dipping, knife coating and the like. Ä. are applied. The coating compositions are usually applied in accordance with a dry film layer thickness between 20 ° and 90 μm, preferably 30 to 45 μm. The coating compositions of the invention reach a degree of dryness 6 according to DIN 53 150 at room temperature between 2 and 4 h; this degree of dryness is achieved considerably more quickly by forced drying at temperatures of up to 140.degree. Set the most favorable drying conditions This depends on the type, size and geometry of the objects to be coated.

The coating compositions can be applied to a wide variety of substrates, such as e.g. δmetal, wood, glass and plastic surfaces, the coating compositions being particularly suitable for coating primed or non-primed metals or steel. Typical areas of application are the coating of glass fiber reinforced plastics, steel which has been treated with zinc phosphate or iron phosphate and metal substrates which have been precoated with conventional alkyd or epoxy primers, e.g. galvanized steel, chromated aluminum, die-cast aluminum, cast iron etc.

The coating compositions according to the invention based on aliphatic isocyanates are mainly used for top coats in the industrial sector due to their better weather resistance, e.g. for machine parts and other everyday objects of various sizes and geometries, especially for top coating large machines, e.g. Agricultural machines, construction machines, e.g. Cranes, excavators, shovel loaders, etc. . used. But they are also 5 for the area of automotive serial and repair painting, the area of truck painting as well as for the painting of railway equipment and the like. . and suitable as a primer in the industrial sector.

Coating agents based on aromatic isocyanates are mainly used as a primer and as a top coating in the field of interior applications, for example for the coating of tools, metalworking machines, beverage filling machines and tool processing machines. 1 The invention will now be explained in more detail on the basis of exemplary embodiments. All information on parts and percentages are weight information, unless something else is explicitly stated.

example 1

9 parts of a commercially available medium-oil, air-drying polyester resin a based on soy fatty acids with an oil content / triglyceride content of 46% and a phthalic anhydride content of 22% with an OH number (solvent-free) of 75 mgKOH / g, an iodine number ( 50% solution) <10 mgl ₂ / g, an acid number lδ (solvent-free) <10 mgKOH / g and a viscosity (60% in xylene / butyl acetate 80:20 at 20 °) from 30 to 40 s according to DIN 53 211 , dissolved 80% in xylene / butyl acetate 1: 1, 5.75 parts of a branched hydroxyl-containing polyester b based on tri-20methylolpropane, 1,3-trimethylpentanediol, hexahydrophthalic anhydride and phthalic anhydride with a content of 0.1 mol. % Trimethylolpropane, an acid number (solvent-free) of 10 to 14 mgKOH / g, an OH number (solvent-free) of 132 mgKOH / g and a viscosity of 3.3 to 4.5 dPas at 23 ° C (60% Solution in Solvent Naphtha ^® } 5.25 parts of a with synthetic fatty acids m modified polyester c with an OH number (solvent-free) of 120 mgKOH / g, an acid number (solvent-free) of 5 to 10 mgKOH / g and a viscosity of 5.8 to 6.5 dPas at 23 ° C

(70% solution in Solvent NaphthaSj), dissolved 80% in Solvent Naphtha®, 0.4 parts of a commercially available deaerator, 0.5 parts of a commercially available wetting agent, 0.9 parts of a commercially available leveling agent, 0.4 δ parts of one commercial anti-settling agent, 25 parts of rutile-type titanium dioxide, 2 parts of iron oxide 1 black, 10 parts synthetic barium sulfate, 3 parts xylene and 1 part butyl glycol acetate are pre-dispersed and then ground to a Hegman fineness of 8 µm. This mixture is mixed with 28 parts of the above-described polyester resin a, 1.3 parts of a dry substance mixture of 0.4 parts of cobalt octoate solution (50% in white spirit) and 0.9 parts of lead octoate solution (60% in white spirit), corresponding to a content of 0.08% cobalt and 100.73% lead, in each case based on the solids content of the polyester resin a, 0.2 parts of a commercially available anti-skin agent, 1.25 parts of white spirit 145/200 °, 0.1 parts of a commercially available Accelerator, 1.0 part of a light stabilizer combination, 151.25 parts of 1-methoxypropyl acetate-2 and 3.70 parts of butylglycol acetate were added and processed to form a homogeneous mixture. The coating component II thus obtained has a solids content of 77% and a viscosity each. 60 s according to DIN 53 211. 20,100 parts of this paint component II are mixed with 32 parts of a hardener component II-1 (solids content 38.3%, viscosity 12-14 s according to DIN 53 211) (OH: NCO equivalent ratio - 1: 1). A hardener component II-1 is a mixture of 2523 parts of a commercially available aliphatic polyisocyanate (100%) with an NCO content of 23%, a viscosity of 2500 mPas ± 1000 mPas at 23 ° C. and an equivalent weight of 183, 21 , 6 parts of a commercial solution of an aliphatic polyisocyanate (70% in Solvesso 100®) with an NCO content of 11.5%, based on the 70% solution, a viscosity of 2500 mPas + 1000 mPas at 23 ° C and an equivalent weight of 365, 0.2: parts of a commercially available stabilizing agent based on a monoisocyanate and

55.4 parts of a solvent mixture of 27.1 parts - • -len Solvesso® 150, 61.74 parts xylene and 10.80 parts len butylglycol acetate used.

The coating composition 1 thus obtained has a solids content of ⁵ 67.6% and a viscosity of 18 - 20 s at 53 211 DIN.

Phosphated steel sheets are provided with a commercially available 1-component primer based on epoxy diesters (dry film thickness 25 - 35 / um). The coating agent 1 is then applied electrostatically to this hardened primer by the airless spraying method (dry film layer thickness 35-45 μm). The coating agent 1 shows good spray mist absorption behavior (spray mist absorption max. 30 min).

The coating composition can also be applied without problems using the air-mix spraying method, conventional spraying with air atomization and with the aid of the high-speed bell. 0

At room temperature, the degree of dryness 6 according to DIN 53 150 is reached after 3 to 4 h. With a forced drying of 80 ° C. for a period of 20 min and subsequent storage at room temperature, 5 degree of dryness 6 according to DIN 53 150 is reached after only 1 h.

After storage for 7 to 10 days at room temperature, the coatings obtained are subjected to various tests. The following results are achieved: 1

Gloss (according to Gardner, 20 ° angle): ±. 80

Erichsen depression: 7 mm

Shot peening test according to DIN 59 154: 8000 ⁵ Buchholz hardness ASTM D 3363:> 100

Pendulum hardness according to König: ∑ 100 s

Elasticity conical mandrel ASTMD 522:> 32%

Constant condensation water according to DIN 50 017: 288 h ok

(Assessment of the degree of blistering according to 0DIN 53 209 and the degree of rusting according to 53 210: m2g2)

Salt spray test DIN 50 021: 240 h ok

(Assessment of the degree of bubbles according to DIN 53 209 and the degree of rust according to DIN 53 210: m2g2)

Detergent resistance ¹ ) compared to a 1% solution, pH 12, 15 min. 80 ° C: good

Hydraulic oil resistance ²⁾ at 120 ° C: 100 h water storage ³⁾ : 100 h petrol resistance ^): good solvent resistance ⁵ ): good 0 weather resistance (2000 h weather-o-meter): gloss drop 20% color deviation ΔE (according to CIE guidelines): . 1

1) The detergent resistance was checked by δ the test sheet after appropriate aging (10 days room temperature) both in a 1% alkaline washing solution with a pH value of 11-12, as well as in a 1%, light acidic washing solution (iron phosphating, pH 4-5) is immersed at 80 ° C for 15 min.

2) The hydraulic oil resistance was checked by immersing the test sheet after aging (10 d) in hydraulic gear oil (eg Type Fluid 41 from Shell) for 100 hours at a temperature of 135 ° C. 1

3) During the water storage test, it was examined whether bubbles or rust spots in distilled water after storage for 100 hours

5 are visible.

4) The gasoline resistance was tested by dropping super gasoline on the test specimen. It is assessed whether the coating is loosened or raised.

10 tung. The gasoline acts until the gasoline has evaporated, at most 45 minutes.

5) The solvent resistance was checked by dropping various solvents onto the test specimen. The dissolving or raising of the coating is assessed. The solvent acts on the coating during the time until the solvent has evaporated, but at the longest for 45 minutes. 0

The following solvents were tested:

Petrol 180/210 - petrol 145/200

Solvesso® 150 5 n-butyl acetate 98 ig

Methoxypropyl acetate

Solution benzene

Isobutanol

Xylene 0 butyl glycol acetate 1

Example 2

Analogously to Example 1, a paint component I-1 with δ a solids content of 77% and a viscosity of 2 60 s according to DIN 53 211 is produced.

100 parts of this paint component I-1 are mixed with 26 parts of a hardener component II-2 (viscosity 13-16 s according to DIN 53 211) (OH: NCO equivalent ratio - 1: 1).

A hardener component II-2 is a mixture of 23 parts of a commercially available aliphatic polyisocyanate (100%) with an NCO content of 23%, a viscosity of 2500 mPas ± 1000 mPas at 23 ° C. and an equivalent weight of 183 , 23 parts of a commercially available aliphatic polyisocyanate (100%) with an NCO content of 20 to 23% and a viscosity of 130 to 160 mPas at 23 ° C. and 54 parts of a solvent mixture of 14.15 parts

Solvesso® 150, 56.60 parts of xylene, 10.40 parts of solution benzene, 9.4 parts of butyl glycol acetate and 9.45 parts of butyl diglycol acetate were used. The coating agent 2 obtained in this way has a solids content of approximately 72% and a viscosity of 22 to 25 s in accordance with DIN 53 211.

This coating agent 2 is applied analogously to Example 1 on phosphated steel sheets provided with a commercially available 1-component primer based on epoxy diesters.

At room temperature, the degree of dryness 6 according to DIN 53150 is reached after 3 to 4 h. With a forced drying of 80 ° C for 20 minutes and subsequent storage at room temperature, the degree of dryness 6 according to DIN 53 150 is reached after only 1 h. 1

After storage for 7 to 10 days at room temperature, the coatings obtained are subjected to various tests analogously to Example 1. The following results are achieved:

Gloss (according to Gardner, 20 ° angle): 2.80

Erichsen depression: 7 mm

Shot peening test according to DIN 59 154: 8000 l, hardwood hardness ASTM D 3363:> 100

Pendulum hardness according to König: 2,100 ε

Elasticity conical mandrel ASTMD 522;> 32%

Constant condensation water according to DIN 50 017: 288 h ok

(Assessment of the degree of bubbles according to IδDIN 53 209 and the degree of rust according to 53 210: m2g2)

Salt spray test DIN 50 021: 240 h ok

Detergent resistance ¹ ) against a 1% θ solution, pH 12, 15 min. 80 ° C: good

Hydraulic oil resistance ² ) at 120 ° C: 100 h water storage ³⁾ : 100 h petrol resistance ⁴⁾ : good solvent resistance ⁵⁾ : good 5 weather resistance (2000 h weather-o-meter) j gloss drop I 20% color deviation ΔE (according to CIE guidelines) ..1

9 parts of the commercially available polyester resin a (80%) described in Example 1, 5.75 parts of the branched polyester b (73%) described in Example 1, 5.25 parts of the modified polyester described in Example 1 Certified polyester c (80%), 0.4 part of a commercial deaerator, 0.5 part of a commercial wetting agent, 0.90 part of a commercial leveling agent and 0.4 part of a commercial ⁵ anti-settling agent, 16 parts Chrome oxide green, 7 parts rutile-type titanium dioxide, 15 parts synthetic barium sulfate,

3 parts of xylene and 1 part of butyl glycol acetate are predispersed and then ground to a Hegman fineness of 10 μm. This mixture is stirred with 28 parts of the polyester resin a described in Example 1, 0.7 parts of a dry substance mixture from 0.2 parts of a cobalt octoate solution, 50% in white spirit, and 0.7 parts of a lead octoate solution, 60% in white spirit, corresponding to a content of 0.04% cobalt and 0.4% lead, each based on the solids content of the polyester resin a, 0.2 parts anti-skin agent, 1.40 parts gasoline 145/200, 1, 40 parts of 1-methoxypropyl acetate-2 and 4.10 parts of butyl glycol acetate were added and the mixture was processed to a homogeneous mixture. The lacquer component 1-2 obtained in this way has a solids content of approx. 77% and a viscosity i 80 s according to DIN 53 211.

100 parts of this paint component 1-2 are mixed with 17 parts of a solution of an aromatic polyisocyanate (from 66 parts of the commercial solution of an aromatic isocyanate with an NCO content of 17.3% and an equivalent weight of 243, in each case based on pure isocyanate, 24 parts of xylene, 5 parts of gasoline 145/200 and 5 parts of methoxypropyl acetate) with an NCO content of 7.5%, a viscosity of 13 to 15 s according to DIN 53 211 and an equivalent weight of 560, each based on the 44% strength solution Lö¬ offset (OH: NCO equivalent ratio _"ι: o, 5). The coating agent 3 obtained in this way has a solids content of approximately 70% and a viscosity of 23 to 28 s in accordance with DIN 53 211.

This coating agent 3 is applied by means of the airless spraying process ⁵ electrostatically to phosphated steel sheets which have previously been provided with a 1-component primer based on epoxy ester (dry film thickness 25 μm) (dry film thickness 35 μm). The coating agent 3 l ° shows a good spray mist absorption behavior (spray mist absorption max. 30 min).

The coating agent can also be applied easily using the air-mix spraying method, conventional spraying with air atomization and with the help of the high-rotation bell.

At room temperature, the degree of dryness 6 according to DIN 53 150 is reached after 2 h. In a forced drying of 80 C ^β over a period of 20 min and 0anschließender storage at room temperature of the drying degree is 6 according to DIN 53 150 after 30 min er¬ ranges.

After storage for 7 to 10 days 5 At room tur _ra NEN tests are subjected to the coatings obtained verschiede¬. The following results are achieved:

Gloss (according to Gardner, 60 ° angle) ∑ 80 θErichsen depth: 4 mm

Buchholz hardness ASTM D 3363: 2.100

Pendulum hardness after king; ∑ 100 s

Condensation water constant climate according to DIN 50 017: 192 h OK

Salt spray test DIN 50 021: 168 h ok 1 (assessment of the degree of bubbles according to DIN 53 209 and the degree of rust according to DIN 53 210: m2g2)

In addition, the coatings are characterized by good resistance to aggressive coolants (e.g. Syntilo R from Castrol), drilling emulsions and lubricating and hydraulic oils. The coatings are also resistant to hot swarf and can be cleaned with the usual cleaning agents and solvents. After all, they are insensitive to weak alkali eyes, fat-resistant, waterproof and durable to fruit juices and alcohol.

¹⁵ Example 4

11.60 parts of the polyester resin a (80%) described in Example 1, 5.90 parts of the branched polyester b (73%) described in Example 1, 6.0 parts of the modified polyester described in Example 1 c, 0.4 parts of a commercially available deaerator, 2.50 parts of 1-methoxypropyl acetate-2, 2.0 parts of a commercially available wetting agent, 0.9 parts of a commercially available leveling agent, 0.60 parts of a commercially available anti-settling agent, 1.80 parts of rutile-type titanium dioxide, 11 parts of synthetic barium sulfate, 4.50 parts of chrome yellow, 2.80 parts of iron oxide yellow, 2.40 parts of iron oxide red, 1.10 parts of carbon black, 1 part of xylene and 3 parts of butyl glycol acetate are yaws predispersion 0 followed by _/ to ground to a Hegman fineness 5 to 8 This mixture is stirred with 27.60 parts of the polyester resin a (80%) described in Example 1, 0.45 parts of a cobalt toctate solution (50% in white spirit) and 1.0 part of δ lead octoate. Solution (60% in white spirit), corresponding to a content of 0.08% cobalt and 0.8% Lead, in each case based on the solids content of the polyester resin a, 0.2 part of anti-skin agent, 0.10 part of accelerator, 2.50 part of gasoline 145/200 °, 1.50 part of Solvesso® 150, 7.0 part of butyl glycol acetate and 2.15 parts of xylene and processed to a homogeneous mixture.

The lacquer component 1-3 obtained in this way has a solids content of approx. 68% and a viscosity of 45 to 55 s in accordance with DIN 53 211. 100 parts of this lacquer component 1-3 are mixed with 29 parts of the hardener component II-2 described in Example 2 (OH: NCO equivalent ratio 1: 1.1).

The coating agent 4 thus obtained has a δ solids content of 64% and a viscosity of 20 to 22 s according to DIN 53 211.

This coating agent 4 is applied analogously to Example 1 on phosphated steel sheets provided with a commercially available 1-component primer based on epoxy diesters.

At room temperature, the degree of dryness 6 according to DIN 53150 is reached after 3 to 4 h. With a forced drying of 80 ° C for a period of 20 min and subsequent storage at room temperature, the degree of dryness 6 according to DIN 53150 is reached after only 1 h.

Gloss (according to Gardner, 20 ° angle): ∑ 80 Erichsen depth: 7 mm shot peening test according to DIN 59 154: 8000 Buchholz hardness ASTM D 3363:> 100 1 Pendulum hardness according to König: ∑ 100 s elasticity conical mandrel ASTMD 522> 32% constant condensation water according to DIN 50 017: 288 h OK (assessment of the degree of bubbles according to 5DIN 53 209 and the degree of rust according to 53 210: m2g2) Salt spray test DIN 50 021: 240 h OK ( Assessment of the degree of bubbles according to DIN 53 209 and the degree of rust according to DIN 53 210: m2g2)

Detergent resistance ¹⁾ to a 1% solution, pH 12, 15 min. 80 ° C: good

Hydraulic oil resistance ² ) at 120 ° C: 100 h water storage ³ ): 100 h petrol resistance ⁴ ): good solvent resistance ⁵ ): good resistance to weathering (2000 h weather-o-meter): loss of gloss i 20% color deviation ΔE (according to CIE guidelines) 1

Comparative example 1

19 parts of the polyester resin a (80%) described in Example 1, 0.4 part of a commercially available deaerator, 0.5 part of a commercially available wetting agent, 50.9 parts of a commercially available leveling agent, 0.6 part of a commercially available anti-settling agent , 2.5 parts of rutile-type titanium dioxide, 10.3 parts of inorganic yellow pigment, 3 parts of organic yellow pigment, 14 parts of synthetic barium sulfate, 0.1 part of organic orange pigment, 4.5 parts of methoxypropyl acetate and 3 parts of xylene predispersed and then ground to a Hegman fineness of 8 μm. This mixture is stirred with 31 parts of the polyester resin a described above, 1.45 parts 5 of a dry substance mixture from 0.45 parts of cobalt toatate solution (50% in white spirit) and 1 part of lead oil. 1 toat solution (60% in white spirit), corresponding to a content of 0.07% cobalt and 0.6% lead, each based on the solids content of the polyester resin a, 0.2 parts of a commercially available anti-skin agent, δ o, l parts of a commercially available accelerator and 8.45 parts of xylene are added and processed to form a homogeneous mixture. The paint component I-VI thus obtained has a solids content of 73% and a viscosity _ 85s according to DIN 53 211. 10100 parts of this paint component I-VI are mixed with 29 parts of the hardener component II-1 described in Example 1 (solids content 38.3%) (OH: NCO equivalent ratio «1: 1). The coating agent VI thus obtained has a solids content 5 of approximately 65% and a viscosity of 25-35 s in accordance with DIN 53 211.

This coating agent is applied to phosphated steel sheets, which have previously been provided on the basis of epoxy ester having an 1-component Grun- dation (dry chichtdicke 0 _mS fii 25 / um), applied (layer thickness Trockenfilm¬ 25 - 35 _/ um). The coating agent VI is applied according to the most varied of methods, with color differences being observed in the case of different applications (electrostatic or pneumatic, etc.). In comparison to coating agent 1 of example 1, this coating agent VI of comparative example 1 also shows a shorter spray mist absorption time and a poorer stability, which requires a higher viscosity. In addition, problem-free defoaming of coating agent VI is not possible with the various application processes. In addition, the resulting coatings have a lower weather resistance than the coatings of Example 1 (higher loss of gloss and higher color deviation than in Example 1) and less l Erichsen cupping values and a lower hardness according to DIN 53 153.

Comparative Example 2

5

20 parts of the polyester resin a (80%) described in Example 1, 0.4 part of a commercially available deaerator, 0.5 part of a commercially available wetting agent, 0.9 part of a commercially available flow control agent, 0.4 part of a Commercial anti-settling agents, 25 parts of rutile-type titanium dioxide, 2 parts of black iron oxide, 10 parts of synthetic barium sulfate, 1 part of butylglycol acetate and 3 parts of xylene are predispersed and then ground to a Hegman fineness Iδ of 8 μm. This mixture is stirred with 28 parts of the polyester resin a described above, 1.3 parts of a dry substance mixture of 0.4 part of cobalt octoate solution (50% in white spirit) and 0.9 part of lead octoate solution (60% in white spirit ), 0 corresponding to a content of 0.062% cobalt and

0.59% lead, in each case based on the solids content of the polyester resin a, 0.2 part of a commercially available anti-skin agent, 1.0 part of a light protection agent combination, 0.1 part of a commercially available δ accelerator, 1.25 parts of gasoline 145/200 , 1.25 parts of methoxy propyl acetate and 3.75 parts of butyl glycol acetate are added and processed to give a homogeneous mixture. The coating component I-V2 thus obtained has a solids content of 78% and a viscosity of 0 80s in accordance with DIN 53 211.

100 parts of this paint component I-V2 are mixed with 28 parts of the hardener component II-1 (solids content 38.3%) described in Example 1 (OH: NCO equivalent ratio = 1: 1). The δ coating agent V2 thus obtained has a solids content of approx. 67% and a viscosity of 25-35 s iDIN 53 211. This coating agent is applied to phosphated steel sheets which have previously been provided with a 1-component primer based on epoxy diesters (dry film thickness 25 µm), (dry film thickness 25-35 µm). The coating agent V2 is applied according to the most varied of methods, with color differences being observed in different applications (electrostatic or pneumatic, etc.). In comparison to coating agent 1 of example 1, this coating agent V2 of comparative example 2 also shows a shorter spray mist absorption time and a poorer stability, which requires a higher viscosity. In addition, problem-free defoaming of the coating agent V2 is not possible in the various application processes. In addition, the resulting coatings have a lower weather resistance than the coatings of Example 1 (higher gloss drop and higher color deviation than in Example 1) as well as lower Erichsen cupping values and a lower hardness according to DIN 53 153.

Claims

1 claims:

1. Coating agent which contains a binder component based on polyester and a hardener component based on isocyanate, characterized in that the coating agent as a binder comprises a mixture of

10 a) 30 to 94% by weight of at least one hydroxyl-containing polyester resin with an OH number of 40 to 140 mgKOH / g and an oil content of 25 to 57%,

lδ b) 3 to 50 wt .-% of at least one branched hydroxyl-containing polyester based on cycloaliphatic and / or aromatic di- and / or polycarboxylic acids with an OH number of 100 to 200 mgKOH / g and a content of tri- and / or higher-functional alcohols and / or carboxylic acids of at least 15 mol%, based on the total content of alcohols and carboxylic acids, and

⁵ c) 3 to 50% by weight of at least one polyester modified with synthetic fatty acids with an OH number of 80 to 150 mgKOH / g and a content of synthetic fatty acids of 35 to 50% by weight, based on the weight 0 of the modified polyester, the sum of the parts by weight of components a to c being 100% by weight.

2. Coating agent according to claim 1, characterized δ indicates that the coating agent as a binder is a mixture of a) 70 to 90% by weight of at least one hydroxyl-containing polyester resin with an OH number of 40 to 140 mgKOH / g and an oil content of 25 to 57%,

b) 5 to 15% by weight of at least one branched hydroxyl-containing polyester based on cycloaliphatic and / or aromatic di- and / or polycarboxylic acids with an OH number of 100 to 200 mgKOH / g and a content of tri- and / or higher-functional alcohols and / or carboxylic acids of at least 15 mol%, based on the total content of alcohols and carboxylic acids, and

c) 5 to 15% by weight of at least one polyester modified with synthetic fatty acids with an OH number of 80 to 150 mgKOH / g and a content of synthetic fatty acids of 35 to 50% by weight, based on the weight of the contains modified polyester, the sum of the proportions by weight of components a to c being in each case 100% by weight.

Coating composition according to claim 1 or 2, characterized in that the coating composition as component a contains at least one hydroxyl-containing polyester resin with an OH number of 50 to 90 mgKOH / g and an oil content of 40 to 50% and / or as component b at least one branched polyester containing hydroxyl groups based on cycloaliphatic and / or aromatic di- and / or polycarboxylic acids with an OH number of 115 to 150 mgKOH / g and / or as component c at least one with synthetic fatty acids contains modified polyester with an OH number of 115 to 130 mgKOH / g. 1

4. Coating agent according to one of claims 1 to 3, characterized in that the coating agent additionally organic solvent,

'' possibly contains pigments and / or fillers and other customary auxiliaries and additives.

5. Coating agent according to one of claims 1 to 4, characterized in that the coating agent has a viscosity of 18 to 20 s at a temperature of 20 ° C at a solids content of at least 60% by weight.

6. Coating agent according to one of claims 1 to 5, characterized in that the coating agent at least one aliphatic and / or cycloaliphatic polyisocyanate with an NCO content of 18 to 25% and a viscosity of 100 to 200 mPas at 20 ° C, based in each case on the isocyanate without solvent content and, if appropriate, further di- and / or polyisocyanate as hardener.

7. Coating agent according to one of claims 1 to 6, characterized in that the coating agent contains at least one aliphatic di- and / or polyisocyanate as hardener and the hardener is contained in such amounts that the equivalent ratio of the hydroxyl groups of the binder to the isocyanate groups the hardener is between 1: 1 and 1: 1.1.

8. Coating agent according to one of claims 1 to 5, characterized in that the coating agent contains at least one aromatic di- and / or polyisocyanate as hardener and the Hardener is contained in such quantities that the

Equivalent ratio of the Hxdroxylgruppen des

Binder to the isocyanate groups of the hardener is between 1: 0.5 and 1: 0.8. 5

9. A process for the preparation of the coating compositions according to any one of claims 1 to 8, characterized gekenn¬ characterized in that the coating composition by mixing and optionally dispersing a paint component 0 I, which contains the binder and a Lack¬ component II, which contains the hardener, is manufactured.

10. A method for coating plastics and metallic substrates, characterized in that a coating agent according to one of claims 1 to 8 is applied.

11. Use of the coating compositions according to claim

7 for top coating and as a primer in the industrial sector, in particular for top coating large machines.

12. Use of the coating compositions according to claim

8 as a primer in the industrial sector and for

Top coat in the area of interior applications.